Nuclear medicine tomographic imaging techniques, such as single photon emission tomography (SPECT), use electromagnetic radiation to produce images of a patient. For example, the SPECT technique requires administration of a radionuclide to the patient. Gamma photons are emitted by the radionuclide as the radionuclide decays. The emitted gamma photons are detected to produce signals related to the patient (e.g., cross-sectional images). Multiple images can be acquired from multiple angles to construct 3-D image data.